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Informatica: Difference between star and snowflake schema?

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Informatica: Difference between star and snowflake schema?
posted Jul 2, 2015 by Amit Sharma

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1 Answer

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The main difference between star schema and snowflake schema is that

The star schema is highly denormalized and the snowflake schema is normalized. So the data access latency is less in star schema in comparison to snowflake schema. As the star schema is denormalized, the size of the data warehouse will be larger than that of snowflake schema.

Performance wise, star schema is good. But if memory utilization is a major concern, then snow flake schema is better than star schema.

A dimension table will not have parent table in star schema, whereas snow flake schemas have one or more parent tables.

The dimensional table itself consists of hierarchies of dimensions in star schema,whereas hierarchies are split into different tables in snow flake schema. The drilling down data from top most hierarchies to the lowermost hierarchies can be done.

answer Jul 2, 2015 by Manikandan J
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